Method of recovering lead and silver.



No Drawing.

Parleur onirica.

THEODORE G. TIMBY, OF' CHICAGO, ILLINOIS.

` IVIE'IHCI)I QF RECOVERING LEAD AND SILVER.

Specification of Letters Patent.

Patented Mar. 18, 1913.

application sied MarenA 2, raiz. serial no. 681,300.

To all whom it may concern i Be it known that I, THEoDoRE G.,..T.IMBY, a citizen of the United States, residing at Chicago, in the county of Cool; and State -My -invention relates to improvements in methods of recovering leadof Illinois, have invented a certain new and` :.useful Method of Recovering [Lead andy Silver, of which the following is a specifi cation.

andsilver from argentiferous lead-bearing vores, particularly sulid ores containing silver.

l 'Byl ordinarysmelting methodspwhether the 'orebe treatedl in an open hearth, rever'- be'ratory or blast furnace, the silver and lead are recovered together as a mixture vor alloy and they can be separated only by' costly relining processes or by cupeling the talloy withA a conversion of the lead to litha-rgeand recovering the refined silver as a metallic'v residue; or inst commonly by a combination of some of the above mentioned processes.

So tedious and costly are the present rening processes that where but little silver is present it is very frequently left with A'the lead and sold inthe pig lead without charge.'

Also, without regard to the silver, the ree` lining of lead'obtained by furnace treatment,

particularlyblast furnace treatment, of the ore is slow, expensive and entails lossv of me'- tallic values. This is so because at the'ftemperature employed' in a blast furnacethe metal is heated to a temperature whereI it' is actively solvent or absorbent of c ontainiluating metals, asl for instance iron, copper, tin,- arsenic and `antimony. Whether because these contaminating metals are not decomposed from their compounds to such a great-v extent or. because the lead is less absorbent of them atlower temperatures or for some other reason', lead obtained by 'the open hearth or 'reverberatory furnace treatments i is'less impure; but even such lead has to be refined by poling with wood or by steam or by liquation before it is merchantabl'e' as the desirable soft lead.

By methods heretofore proposed for 'electrolyzing argentiferous lead bearing ore,"the

silver and lead have been recovered together thus requiring subsequent separation, and

the treatment would be impractical in the one case, because of the loss or waste o f jelec'- tricity and -because of the expense 1n the other required to maintain the bath at the necessarily high temperature. For example,

new and useful.

it has been proposed' to electrolyze such ore 1n a bath of molten lead compounds, but such treatment would 'be prohibit-ive because of the expense necessary to maintain the bath at the required-high temperature and at best would produce only an alloy of lead and 'silver Also, it. has been proposed to electrolyze 'such ore by a process wherein t-he ore, usurequiring subsequent separation.l

in 'the form ofV lead sulid, was piled 'around the anode and partially electrolyzed in such bath. While some electrolysis of the om can be secured by,such' procedure, such channels'of the solution because of the conduct-'lviityof the dissolved electrolyte all such electricity 1s wastedandhas-no effect what-` ever upon the ore, and as'both the lead and silver collect on the cathode they must be subsequently separated by refining.

have discovered that-by employing cast argentiferous llead-bearing ore, in any convenient form such as bars or cakes, as the anode of anlelectrolytic cell containing a solution in water of a suit-able'electrolyte` l can more quickly and cheaply separate the lead and silver therefrom and also can independently recover them.

.In practising my invention I prepare the bars or cakes of argentiferous llead-bearing ore used as anodes by fusing theore, usually lead sulfid containing silver, preferably in a reverberatory hearth` in which the atmosphere of the chamber abovetheore is kept practically reducing by allowing' it to remain full of thegaseous products of combustion .from the re box, and, then casting or molding the fused ore into bars or cakes in suitable molds of refractorymaterial. In practiceflfind that satisfactory results are obtained when thesebars or cakes are `in the form ofslabs approximately eighteen inches long, twelve -.in'c es wide and two inches Y thick, provided/with suitable heads for'the positive terminal lof the usual .electric .circuit; it is -of course understood that these dimensions .and forms'may be varied. One or more ofsuch anodes are arranged and supported with their bodies immersed 1n the liquid of an electrolytic cell containing a suitable electrolyte dissolved in Water, and' 7 hij? he cell 01' apparatus iS equipped and decimo Cument 1s through the anode in any usua manner the art of eeotroysis, the silva lead-bem'ng or@ anode is Qecrozed he sliver and llbel'ate Suva are ben colced m anyasulm 

